Casein-based formulations as promising controlled release drug delivery systems

Increased Oral Bioavailability of Resveratrol by Its Encapsulation in Casein Nanoparticles

Resveratrol is a naturally occurring polyphenol that provides several health benefits including cardioprotection and cancer prevention. However, its biological activity is limited by a poor bioavailability when taken orally. The aim of this work was to evaluate the capability of casein nanoparticles as oral carriers for resveratrol. Nanoparticles were prepared by a coacervation process, purified and dried by spray-drying. The mean size of nanoparticles was around 200 nm with a resveratrol payload close to 30 μg/mg nanoparticle. In vitro studies demonstrated that the resveratrol release from casein nanoparticles was not affected by the pH conditions and followed a zero-order kinetic. When nanoparticles were administered orally to rats, they remained within the gut, displaying an important capability to reach the intestinal epithelium. No evidence of nanoparticle “translocation” were observed. The resveratrol plasma levels were high and sustained for at least 8 h with a similar profile to that observed for the presence of the major metabolite in plasma. The oral bioavailability of resveratrol when loaded in casein nanoparticles was calculated to be 26.5%, 10 times higher than when the polyphenol was administered as oral solution. Finally, a good correlation between in vitro and in vivo data was observed.

Novel anti-inflammatory film as a delivery system for the external medication with bioactive phytochemical "Apocynin"

PURPOSE

Recently, Apocynin (APO) has emerged as a bioactive phytochemical with potent antioxidant and anti-inflammatory properties. No reports have been published so far concerning its topical application as a pharmaceutical dosage form for prospective use. To the best of our knowledge, this is the first study to fabricate novel anti-inflammatory film for external medication with APO.

METHODS

APO film was prepared using casein (CAS) as a natural protein film former by solvent casting technique. The medicated film was extensively evaluated in terms of its various physicochemical characteristics, ex vivo skin permeation profile, stability, and finally in vivo anti-inflammatory activity on carrageenan-induced rat paw edema.

RESULTS

The film represented satisfactory mechanical properties along with good flexibility. Fourier transform-infrared spectroscopy, differential scanning calorimetry, and X-ray diffractometry revealed possible solubility of APO in the amorphous CAS and inter- and intramolecular hydrogen bonding between the film components. The ex vivo skin permeation results of the medicated film demonstrated non-Fickian diffusion mechanism of the permeated drug. Application of APO film to rat paw before carrageenan-induced paw edema or after induction disclosed eminent anti-inflammatory activity expressed by marked decrease in paw swelling (%) and increase in edema inhibition rate (%). In addition, histopathologic examination revealed a significant decrease in inflammatory scores. The immunohistochemical expression levels of both nuclear factor kappa B and cyclooxygenase-2 were significantly suppressed.

CONCLUSION

These results indicated that CAS film could be applied as a promising external delivery system for the anti-inflammatory APO.

Dual-targeted casein micelles as green nanomedicine for synergistic phytotherapy of hepatocellular carcinoma

In recent years, green nanomedicines have made transformative difference in cancer therapy researches. Herein, we propose dual-functionalized spray-dried casein micelles (CAS-MCs) for combined delivery of two phytochemicals; berberine (BRB) and diosmin (DSN) as targeted therapy of hepatocellular carcinoma (HCC). The nanomicelles enabled parenteral delivery of the poorly soluble DSN via its encapsulation within their hydrophobic core. Moreover, sustained release of the water soluble BRB was attained by hydrophobic ion pairing with sodium deoxycholate followed by genipin crosslinking of CAS-MCs. Dual-active targeting of MCs, via conjugating both lactobionic acid (LA) and folic acid (FA), resulted in superior cytotoxicity and higher cellular uptake against HepG2 cells compared to single-targeted and non-targeted CAS-MCs. The dual-targeted DSN/BRB-loaded CAS-MCs demonstrated superior in vivo anti-tumor efficacy in HCC bearing mice as revealed by down regulation of cell necrosis markers (NF-κB and TNF-α), inflammatory marker COX2, inhibition of angiogenesis and induction of apoptosis. Histopathological analysis and immunohistochemical Ki67 staining confirmed the superiority of the dual-targeted micelles. Ex-vivo imaging showed preferential liver-specific accumulation of dual-targeted CAS-MCs. Overall, this approach combined the benefits of traditional herbal medicine with nanotechnology via LA/FA-CAS-MCs loaded with BRB and DSN as a promising nanoplatform for targeted HCC therapy.

Chitosan:β-glucan particles as a new adjuvant for the hepatitis B antigen

The development of new vaccine adjuvants is urgently needed not only to enable new routes of vaccine administration but mostly to go beyond protective humoral immunity, often insufficient to fight infectious diseases. The association of two or more immunopotentiators or mimicking pathogen physicochemical properties are strategies that can favor powerful and more balanced Th1/Th2 immune responses. Therefore, the present work aimed to combine both chitosan and β-glucan biopolymers in the same particle, preferably with surface β-glucan localization to simulate the cell wall of some pathogens and to stimulate the immune cells expressing the Dectin-1 receptor. Chitosan:β-glucan particles (ChiGluPs) were developed through a chitosan precipitation method. The chitosan was precipitated into a β-glucan alkaline solution followed by genipin crosslink. The optimized method produced particles with a mean diameter of 837 nm for ChiPs and 1274 nm for ChiGluPs. β-glucan surface location was confirmed by zeta potential measurements (+24 mV for ChiGluPs and +36 mV for ChiPs) and zeta potential titration. These new particles showed high antigen loading efficacy and low cytotoxicity. Mice vaccination studies revealed that both ChiPs and ChiGluPs had an adjuvant effect for the hepatitis B surface antigen (HBsAg), with ChiGluPs resulting in serum anti-HBsAg total IgG 16-fold higher than ChiPs, when administered with 1.5 µg HBsAg per dose. Specifically, IgG1 subclass was 5-fold higher and IgG3 subclass was 4-fold higher for ChiGluPs comparing to ChiPs. Overall, the preparation method developed allowed the advantageous combination of β-glucan with chitosan, without chemical functionalization, which represents an additional step toward tailor-made adjuvants production using simple precipitation techniques.

A drug-delivering-drug strategy for combined treatment of metastatic breast cancer

Treatment of metastatic cancer continues to be a huge challenge worldwide. Notably, drug nanocrystals (Ns) in nanosuspensions clearly belong to a type of nanoparticle. Therefore, a question arose as to whether these drug particles can also be applied as carriers for drug delivery. Here, we design a novel paclitaxel (PTX) nanocrystal stabilized with complexes of matrix metalloproteinase (MMP)-sensitive β-casein/marimastat (MATT) for co-delivering MATT and PTX and combined therapy of metastatic breast cancer. The prepared Ns (200 nm) with a drug-loading of >50% were potent in treatment of metastatic cancer, which markedly inhibited MMP expression and activity and greatly blocked the lung metastasis and angiogenesis. In conclusion, employing protein-drug complexes as stabilizers, Ns with dual payloads are developed and are a promising strategy for co-delivery. Furthermore, the developed Ns can target the tumor microenvironment and cancer cells and, as a result, enable efficient treatment for breast metastatic cancer.

Bioactive hydrolysates from casein: generation, identification, and in silico toxicity and allergenicity prediction of peptides

BACKGROUND

Bioactive casein peptides have attracted considerable attention for their applications in industry. However, there is little clarity regarding mass spectrometric profiles for peptides in enzymatic hydrolysates of casein produced under varying conditions. In this study, the compositions of the peptides from casein hydrolysates were compared for different enzyme/substrate ratio (E/S) and hydrolysis times. The toxicity, allergenicity and bioactivity of the identified peptides were assessed in silico.

RESULTS

A total of 70 unique peptides were identified, and there were 28, 21, 13 and 8 peptides from α_s1 -casein, α_s2 -casein, β-casein and κ-casein respectively. The peptide number decreased with the increase in E/S and hydrolysis time. Moreover, peptides with relative molecular mass M_r ranging from 1000 to 1500 Da occupied the highest proportion of 31.43%, and almost all of the peptides showed M_r less than 5000 Da. In silico analysis showed that all of the peptides were non-toxic and non-allergenic, and several of them were assessed by PeptideRanker as having a relatively high likelihood of being bioactive peptides.

CONCLUSIONS

Composition of the peptides in the casein hydrolysates varied with the enzymolysis conditions. This study's results may facilitate the production of target bioactive peptides by controlling E/S and hydrolysis time, which is beneficial for the application of casein peptides in the functional food industry. © 2017 Society of Chemical Industry.

Protein-Based Delivery Systems for the Nanoencapsulation of Food Ingredients

Many proteins possess functional attributes that make them suitable for the encapsulation of bioactive agents, such as nutraceuticals and pharmaceuticals. This article reviews the state of the art of protein-based nanoencapsulation approaches. The physicochemical principles underlying the major techniques for the fabrication of nanoparticles, nanogels, and nanofibers from animal, botanical, and recombinant proteins are described. Protein modification approaches that can be used to extend their functionality in these nanocarrier systems are also described, including chemical, physical, and enzymatic treatments. The encapsulation, retention, protection, and release of bioactive agents in different protein-based nanocarriers are discussed. Finally, some of the major challenges in the design and fabrication of protein-based delivery systems are highlighted.

Translatable High Drug Loading Drug Delivery Systems Based on Biocompatible Polymer Nanocarriers

Most nanocarriers possess low drug loading, resulting in frequently repeated administration and thereby high cost and increased side effects. Furthermore, the characteristics of nanocarrier materials, especially the drug loading capacity, plays a vital role in the drug delivery efficacy. In this review, we focus on the readily translatable polymeric drug delivery systems with high drug loading, which are comprised of biocompatible polymers such as poly(ethylene glycol), poly( N-vinylpyrrolidone), polyoxazoline, natural proteins like albumin and casein, non-natural proteins such as recombinant elastin-like polypeptides, as well as nucleic acids. At the end of this review, applications of these polymeric nanocarriers on the delivery of proteins and gene drugs are also briefly discussed.

Alginate-caseinate composites: Molecular interactions and characterization of cross-linked beads for the delivery of anticandidals

Polysaccharide-protein composites offer potential utility for the delivery of drugs. The objectives of this work were to investigate the molecular interactions between sodium alginate (SA) and sodium caseinate (SC) in dispersions and films and to characterize calcium alginate (CA) beads mixed with SC for the delivery of fluconazole (FZ) and clotrimazole (CZ). The results demonstrated that SA could interact with SC, which caused a viscosity synergism in the dispersions. Hydrogen bonding between the carboxyl or hydroxyl groups of SA and the amide groups of SC led to the formation of soluble complexes that could reinforce the CA beads prepared by calcium cross-linking. The SC-CA beads provided higher drug entrapment efficiency, lower water uptake and erosion, and slower drug release than for the CA beads. The loaded FZ was an amorphous form, but CZ crystals were embedded in the bead matrix due to the low water solubility of this drug. However, SC micellization could enhance the water solubility and efficacy of CZ against Candida albicans. This finding indicates that SA can interact with SC via hydrogen bonding to form complexes and that the anticandidal-loaded SC-CA beads can be used as drug delivery systems and drug reservoirs in tablets for oral candidiasis.

Targeting intracellular MMPs efficiently inhibits tumor metastasis and angiogenesis

Treatment for metastatic cancer is a great challenge throughout the world. Commonly, directed inhibition of extracellular matrix metalloproteinases (MMPs) secreted by cancer cells can reduce metastasis. Here, a novel nanoplatform (HPMC NPs) assembled from hyaluronic acid (HA)-paclitaxel (PTX) prodrug and marimastat (MATT)/β-casein (CN) complexes was established to cure a 4T1 metastatic cancer model via targeting CD44 and intracellular, rather than extracellular, MMPs.

Methods: HPMC NPs were prepared by assembling the complexes and prodrug under ultrasonic treatment, which the interaction between them was evaluated by förster resonance energy transfer, circular dichroism and fluorescence spectra. The developed nanoplatform was characterized via dynamic light scattering and transmission electron microscopy, and was evaluated in terms of MMP-sensitive release and stability. Subsequently, the cellular uptake, trafficking, and in vitro invasion were studied by flow cytometry, confocal laser microscopy and transwell assay. MMP expression and activity was determined by western blotting and gelatin zymography. Finally, the studies of biodistribution and antitumor efficacy in vivo were performed in a mouse 4T1 tumor breast model, followed by in vivo safety study in normal mouse.

Results: The interaction between the prodrug and complexes is strong with a high affinity, resulting in the assembly of these two components into hybrid nanoparticles (250 nm). Compared with extracellular incubation with MATT, HPMC NP treatment markedly reduced the expression (100%) and activity (50%) of MMPs in 4T1 cells and in the tumor. HPMC NPs exhibited 1.4-fold tumor accumulation, inhibited tumor-growth by >8-fold in volume with efficient apoptosis and proliferation, and suppressed metastasis (>5-fold) and angiogenesis (>3-fold). Overall, HPMC NPs were efficient in metastatic cancer therapy. Conclusions: According to the assembly of polymer prodrug and protein-drug complexes, this study offers a new strategy for constructing nanoparticles for targeted drug delivery, biomedical imaging, and combinatorial treatment. Importantly, via inhibition of intracellular MMPs, metastasis and angiogenesis can be potently blocked, benefiting the rational design of nanomedicine for cancer treatment.

Keratin: dissolution, extraction and biomedical application

Keratinous materials such as wool, feathers and hooves are tough unique biological co-products that usually have high sulfur and protein contents. A high cystine content (7-13%) differentiates keratins from other structural proteins, such as collagen and elastin. Dissolution and extraction of keratin is a difficult process compared to other natural polymers, such as chitosan, starch, collagen, and a large-scale use of keratin depends on employing a relatively fast, cost-effective and time efficient extraction method. Keratin has some inherent ability to facilitate cell adhesion, proliferation, and regeneration of the tissue, therefore keratin biomaterials can provide a biocompatible matrix for regrowth and regeneration of the defective tissue. Additionally, due to its amino acid constituents, keratin can be tailored and finely tuned to meet the exact requirement of degradation, drug release or incorporation of different hydrophobic or hydrophilic tails. This review discusses the various methods available for the dissolution and extraction of keratin with emphasis on their advantages and limitations. The impacts of various methods and chemicals used on the structure and the properties of keratin are discussed with the aim of highlighting options available toward commercial keratin production. This review also reports the properties of various keratin-based biomaterials and critically examines how these materials are influenced by the keratin extraction procedure, discussing the features that make them effective as biomedical applications, as well as some of the mechanisms of action and physiological roles of keratin. Particular attention is given to the practical application of keratin biomaterials, namely addressing the advantages and limitations on the use of keratin films, 3D composite scaffolds and keratin hydrogels for tissue engineering, wound healing, hemostatic and controlled drug release.

Plant protein-based hydrophobic fine and ultrafine carrier particles in drug delivery systems

For thousands of years, plants and their products have been used as the mainstay of medicinal therapy. In recent years, besides attempts to isolate the active ingredients of medicinal plants, other new applications of plant products, such as their use to prepare drug delivery vehicles, have been discovered. Nanobiotechnology is a branch of pharmacology that can provide new approaches for drug delivery by the preparation of biocompatible carrier nanoparticles (NPs). In this article, we review recent studies with four important plant proteins that have been used as carriers for targeted delivery of drugs and genes. Zein is a water-insoluble protein from maize; Gliadin is a 70% alcohol-soluble protein from wheat and corn; legumin is a casein-like protein from leguminous seeds such as peas; lectins are glycoproteins naturally occurring in many plants that recognize specific carbohydrate residues. NPs formed from these proteins show good biocompatibility, possess the ability to enhance solubility, and provide sustained release of drugs and reduce their toxicity and side effects. The effects of preparation methods on the size and loading capacity of these NPs are also described in this review.

Investigations on the Effect of Fatty Acid Additives on Casein Micelles: Role of Ethylenic Unsaturation on the Interaction and Structural Diversity

Casein, one of the major constituent of milk protein, is considered to be a good candidate for oral drug delivery system. Also, milk transports various essential fatty acid to blood through dietary supplements. In this study, we have explored the alteration in the structural characteristic in terms of the modulations in the microenvironment of the protein in the presence of different types of fatty acids. Herein, we have observed that the unsaturation of fatty acids mostly affects the structure of casein micelles (CMs) by impinging upon the hydrophobic force of interaction following a decrease in the electrostatic interaction of various amino acid unit. Alteration of such forces is responsible for the increase in the aggregate size, modification in the protein secondary structure, and different morphology of CMs. Fluorescence behavior of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran indicates that the rigidity of the microenvironment is the main characteristic of the fatty acid binding, and the binding constant increases with the fatty acid chain length for saturated fatty acid or with the introduction of unsaturation onto it. Fluorescence lifetime imaging microscopy study indicates that the microstructure of CMs becomes more compact in the presence of unsaturated fatty acids, and this is also responsible for the increase in the diffusion time of the probe. Moreover, decrease in the fluorescence of extrinsic probe 8-anilinonaphthalene-1-sulfonate with the addition of unsaturated fatty acid reveals that these fatty acids alter the electrostatic interaction between casein units, more specifically in case of the surface-bound κ-casein. Therefore, this study provides a very useful information on the binding of fatty acids and helps to evaluate other fatty acid, as well as different small molecules binding in the applicative medicinal purpose.

Alternative foaming agents for topical treatment of ulcerative colitis

Approximately 907,000 Americans currently suffer from ulcerative colitis, a condition characterized by inflammation of the large intestine or rectum. Treatment of this disease often includes anti-inflammatory medication or immunosuppressants. Here foams are an attractive delivery platform, offering relatively high bioavailability, low systemic exposure, and improved patient comfort. However, the surfactants that generate these foams may adversely affect the diseased mucosa. Therefore, this project evaluated two alternative surfactants for use in topical drug delivery platforms: sodium caseinate and l-α-phosphatidylcholine. Both were compared to the biocompatible surfactant Pluronic^® F-127 using stability and density tests, and biocompatibility tests performed on mini-guts. Sodium caseinate foams were less stable but denser than Pluronic^® foams; however, they exhibited an unexpectedly low shelf-life. l-α-phosphatidylcholine was an unsuccessful primary foaming agent owing to poor foamability at low concentrations. Mini-gut growth rates were not significantly altered by surfactants, while morphology and an MTT assay identified Pluronic^® as the most biocompatible surfactant at higher concentrations. These results clarify the possible challenges that the tested surfactants may present in topical delivery platforms and show the relevance of permeability to tissue-surfactant interaction tests. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1448-1456, 2018.

Crosslinked casein-based micelles as a dually responsive drug delivery system

Crosslinked casein micelles with a dual pH and protease drug triggered release can be applied as a promising hydrophobic drug carrier material.

Structure, gelation, and antioxidant properties of curcumin-doped casein micelle powder produced by spray-drying

The encapsulation of curcumin in micellar caseins (MCs) and the production of powder were performed by spray-drying.

Validation of therapeutic anti-inflammatory potential of Arjuna Ksheera Paka - A traditional Ayurvedic formulation of Terminalia arjuna

Arjuna Ksheera Paka (AKP), a traditional Ayurvedic formulation of Terminalia arjuna (T. arjuna) bark powder is used for its cardioprotective effects. However, its anti-inflammatory efficacy remained unexplored. In the present study, AKP was prepared in cow milk (as per standard Ayurvedic procedure) and compared with standard hydroalcoholic extract (HA) of T. arjuna. The extracts were analyzed for gross phytoconstituents levels, and their antioxidant activity was assayed by DPPH free radical scavenging activity and inhibition of lipid peroxidation. The in vivo anti-inflammatory activity of AKP and HA was studied in carrageenan-induced hind paw biphasic edema in C57BL/6 mice (at 200, 400 and 800 mg/kg BW). The percentage extraction yield of AKP was two folds higher than HA implying that the phytoconstituents in AKP were diluted by a factor of 0.5. The total polyphenol content of HA was (3.8 times) higher than AKP and the antioxidant activity of HA was also higher compared to AKP. Both the extracts, however, showed significant (p < 0.05) anti-inflammatory activity in reducing paw edema in mice. The efficacy of HA was more than AKP at early phase of inflammation, whereas, in the late phase of inflammation AKP was more efficacious and equipotent to HA. Thus, regardless of low in vitro antioxidant activity, AKP exhibited potential in vivo anti-inflammatory activity. The higher efficacy of AKP could be due to the presence of milk solids. These milk solids may act as adjuvants to T. arjuna's phytoconstituents, contributing to their sustained bioavailability, leading to higher in vivo anti-inflammatory efficacy at lower drug concentrations.

Nanosuspensions of a new compound, ER-β005, for enhanced oral bioavailability and improved analgesic efficacy

Estrogen receptor-β005 (ER-β005) is a novel compound developed by our group; however, its application has been greatly hindered due to its low solubility. A nanosuspension of insoluble drugs is a nanoscale colloidal dispersion that has extremely higher drug-loading compared with other nanomedicines. In this study, nanosuspensions of ER-β005 (Nano-ER-β005) stabilized by a food protein, β-casein (β-CN), were prepared via an antisolvent-precipitation method to improve oral absorption and thus promote therapeutic efficacy. Nano-ER-β005, which has a diameter of 110nm and drug-loading of 50%, was developed. Analyses of fluorescence and circular dichroism (CD) spectra demonstrated a strong interaction between β-CN and drug particles in Nano-ER-β005, indicating that β-CN is a potent nanosuspension stabilizer. The oral bioavailability of Nano-ER-β005 was 1.6-fold greater than that of raw drug particles. Additionally, ER-β005 was confirmed to have a strong therapeutic effect against pain reactions in animal models, and inhibition of this effect was significantly increased with Nano-ER-β005 treatment. In conclusion, by using β-CN as a stabilizer, nanosuspensions of ER-β005 were developed and oral absorption was enhanced. Moreover, ER-β005 is a powerful drug that inhibits pain reactions, and its therapeutic efficacy was markedly increased in the Nano-ER-β005.

Potential of Casein as a Carrier for Biologically Active Agents

Casein is the collective name for a family of milk proteins. In bovine milk, casein comprises four peptides: α_S1, α_S2, β, and κ, differing in their amino acid, phosphorus and carbohydrate content but similar in their amphiphilic character. Hydrophilic and hydrophobic regions of casein show block distribution in the protein chain. Casein peptides carry negative charge on their surface as a result of phosphorylation and tend to bind nanoclusters of amorphous calcium phosphate. Due to these properties, in suitable conditions, casein molecules agglomerate into spherical micelles. The high content of casein in milk (2.75 %) has made it one of the most popular proteins. Novel research techniques have improved understanding of its properties, opening up new applications. However, casein is not just a dietary protein. Its properties promise new and unexpected applications in science and the pharmaceutical and functional food industries. One example is an encapsulation of health-related substances in casein matrices. This review discusses gelation, coacervation, self-assembly and reassembly of casein peptides as means of encapsulation. We highlight information on encapsulation of health-related substances such as drugs and dietary supplements inside casein micro- and nanoparticles.

In Vitro and In Vivo Evaluation of Casein as a Drug Carrier for Enzymatically Triggered Dissolution Enhancement from Solid Dispersions

Due to its unique properties, such as biodegradability, biocompatibility, high amphiphilic property, and micelle formation, casein (CS) has been increasingly studied for drug delivery. We used CS as a drug carrier in solid dispersions (SDs) and evaluated the effect of its degradation by trypsin on drug dissolution from the dispersions. SDs of CS and mefenamic acid (MA) were prepared by physical mixing, kneading, and coprecipitation methods. In comparison to pure MA, the dispersions were evaluated for drug-protein interaction, loss of drug crystalinity, and drug morphology by differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Drug dissolution from the dispersions was evaluated in simulated intestinal fluid as enzyme free and trypsin-enriched media. Furthermore, in vivo drug absorption of MA from CS-MA coprecipitate was evaluated in rats, in comparison with a reference SD of polyethylene glycol and MA (PEG-MA SD). Relative to other CS preparations, CS-MA coprecipitate showed the highest loss of drug crystallinity, drug micronization, and CS-MA interaction. CS remarkably enhanced the dissolution rate and extent of MA from the physical and kneaded mixtures. However, the highest dissolution enhancement was obtained when MA was coprecipitated with CS. Trypsin that can hydrolyze CS during dissolution resulted in further enhancement of MA dissolution from the physical and kneaded mixtures. However, a corresponding retardation effect was obtained for the coprecipitate. In correlation with in vitro drug release, CS-MA coprecipitate also showed significantly higher MA bioavailability in rats than PEG-MA SD.

Evaluation of thermal stability of confectionary sunflower protein isolate and its effect on nanoparticulation and particle size of the produced nanoparticles

In this study, the effect of different defatting conditions on heat stability of confectionary sunflower protein isolate (SnPI) and the particle size of the produced nanoparticles was investigated. The evaluated factors included temperatures of defatting (40, 50, and 60 °C), time of defatting (2, 6, and 10 h), and the amount of activated carbon (0, 25, and 50% of sample weight). The results of the central composite design showed a significant effect (P < 0.05) among the studied factors, where denaturation temperature and particle size of SnPI nanoparticles were found to be in the ranges of 75.05-89.12 °C and 268-1594 nm, respectively. Moreover, the interaction of activated carbon with temperature and time of defatting proved to be influential factors for the heat stability of confectionary SnPI.

Soy protein isolate as a nanocarrier for enhanced water dispersibility, stability and bioaccessibility of β-carotene

BACKGROUND

The incorporation of β-carotene, one of the most common pigments or bioactives, into food formulations has attracted increasing interest from the food industry, due to its good nutrition and potential health effects. However, it is poorly soluble and unstable in water, which greatly limits its applications in foods. This work presented an effective approach to improve the water dispersibility, stability and even bioaccessibility of β-carotene, using soy protein isolate (SPI) to perform as effective nanocarriers for this molecule.

RESULTS

The complexation with SPI remarkably improved the water dispersibility and stability against heating and freeze-drying of β-carotene. However, the encapsulation efficiency and stability of β-carotene in the nanocomplexes with SPI were closely dependent on the applied β-carotene-to-protein ratio, at which the complexation occurred. The best improvement of stability was observed at appropriate β-carotene-to-protein ratios, e.g. 10-20 g kg^-1 . The complexation with β-carotene mainly occurred on the surface of SPI nanoparticles, through hydrophobic interactions. The complexation resulted in inter-particle aggregation, in a concentration-dependent manner. Almost all of the β-carotene molecules in the nanocomplexes could be progressively released into the aqueous phase.

CONCLUSION

SPI exhibits a good potential to perform as a nanocarrier for enhanced water dispersibility, stability and bioaccessibility of β-carotene. © 2016 Society of Chemical Industry.

Diverse Applications of Nanomedicine

The design and use of materials in the nanoscale size range for addressing medical and health-related issues continues to receive increasing interest. Research in nanomedicine spans a multitude of areas, including drug delivery, vaccine development, antibacterial, diagnosis and imaging tools, wearable devices, implants, high-throughput screening platforms, etc. using biological, nonbiological, biomimetic, or hybrid materials. Many of these developments are starting to be translated into viable clinical products. Here, we provide an overview of recent developments in nanomedicine and highlight the current challenges and upcoming opportunities for the field and translation to the clinic.

In silico-in vitro-in vivo studies of experimentally designed carvedilol loaded silk fibroin-casein nanoparticles using physiological based pharmacokinetic model

The study aimed to design and develop carvedilol loaded silk fibroin-casein nanoparticles using 3² full factorial design. Silk fibroin and casein concentration were selected as the independent variables and their effect were observed on dependent variables: particle size, polydispersity index, encapsulation efficiency, drug release, and dissolution efficiency. The developed optimized formulation was characterized using fourier transform infrared spectroscopy, differential scanning calorimetry, and Powder X-ray diffraction. Surface morphology of optimized formulation using scanning electron microscopy, transmission electron microscopy, and atomic force microscopy revealed spherical nature of particles without any evidence of aggregation. The optimized formulation showed a 2.04-fold increase in C_max, and 6.87-fold increase in bioavailability as compared to aqueous suspension. The formulation showed sustained release as confirmed by increases in mean residence time. The in vivo in silico simulation using physiologically based pharmacokinetics (PBPK) model and population simulation (100 subjects) revealed a reasonable degree of superimposition of simulated and observed pharmacokinetic parameters based on overall fold error (≤2.0). The enhanced bioavailability with sustained effect demonstrates potential of silk fibroin as an alternative carrier for drug delivery and presents Gastoplus™ as efficient tool for in vivo in silico simulations.

Highly Stretchable and Notch-Insensitive Hydrogel Based on Polyacrylamide and Milk Protein

Protein-based hydrogels have received attention for biomedical applications and tissue engineering because they are biocompatible and abundant. However, the poor mechanical properties of these hydrogels remain a hurdle for practical use. We have developed a highly stretchable and notch-insensitive hydrogel by integrating casein micelles into polyacrylamide (PAAm) networks. In the casein-PAAm hybrid gels, casein micelles and polyacrylamide chains synergistically enhance the mechanical properties. Casein-PAAm hybrid gels are highly stretchable, stretching to more than 35 times their initial length under uniaxial tension. The hybrid gels are notch-insensitive and tough with a fracture energy of approximately 3000 J/m². A new mechanism of energy dissipation that includes friction between casein micelles and plastic deformation of casein micelles was suggested.

Hollow Casein-Based Polymeric Nanospheres for Opaque Coatings

Casein-based hollow polymeric sphere were fabricated through emulsifier-free polymerization coupled with alkali swelling approach. Hollow structure and nanoscale size of casein-based polymeric spheres were verified by TEM, AFM, SEM, and UV-vis spectra. The as-obtained hollow spheres were proved exhibiting superior opaque characteristic. Through adjusting the structural parameters, for example, MAA usages and MAA content in seed to core, sphere film showed tunable visible-light transmittance and antiultraviolet property. The formation mechanism of casein-based hollow sphere has been discussed in depth. Worth mentioning, the resultant hollow polymeric sphere can easily form films itself at room temperature, which would open a new possibility of designing opaque coatings in several fields, such as leather, packaging, paper making, biomedical, and special indoor coating applications.